The Birth Data come in a number of different formats; however, in each case,
the birth microdata file contains birth certificate data from a given calendar year.
Linked Birth/Infant Death data were not collected 1992-1994. However, infant
cause of death is included in the
Multiple Cause-of-Death Data.

Birth Cohort Linked Birth/Infant Death Data
includes all births in a given calendar year occuring within the United States
and all deaths for the infants born during that calendar year who
died before reaching one year of age.
U.S. Territories data are included on separate data files.
The data from the birth certificates
and the death certificates are useful for studying infant mortality.
More recent Linked Birth/Infant Death Data are included in the
Linked Birth/Infant Period Data File below.

Natality Detail Data. includes
all births occuring in a given calendar year within the United States.
The data are based on information abstracted from birth
certificates filed in vital statistics offices of each State and District of Columbia.
U.S. Territories (Puerto Rico, Virgin Islands, and Guam) are included on separate
data files beginning in 1994.

Linked Birth Infant Death Period Data
includes all births in a given calendar year occuring within the United States
and all infant deaths in the given calendar year.
The data from the birth certificates
and the death certificates are useful for studying infant mortality.
U.S. Territories data are included on separate data files.

1995-2002 Perinatal Mortality Data.
combines the Period Linked Birth/Infant Death Data and the Fetal Death Data.
Infant deaths and fetal deaths can be distinguished using the variable OUTCOME.
The Fetal Death Data File includes all fetal deaths in a given calendar year
occuring in the United States and the District of Columbia.
U.S. Territories data are included on separate data files.
Fetal death registration requirements
vary; however, most areas require reporting of fetal deaths of gestations of 20 weeks
or more. Deprecated.

1995-1998 Matched Multiple Births Data.
allows for analysis of characteristics (such as gender combination of the set,
outcome of the set, birthweight differences among set mates) of sets of births
and fetal deaths in multiple deliveries through a set member identifier.